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Enjoy exceptional optical and tracking performance for astrophotography, or research, with the CDK500 package! Includes a CDK20 optical tube and L-500 mount.
- CDK20 optical tube:
- f/6.8 and 3454mm focal length
- No coma, no off-axis astigmatism, and no field curvature.
- Pinpoint stars across a 52mm image circle.
- Rock solid fused silica mirrors with low thermal expansion.
- Carbon fiber optical tube assembly for rigidity and fast cooling.
- Simple secondary mirror collimation thanks to the fixed primary mirror.
- L-500 direct drive mount:
- Zero periodic error, zero backlash, and minimal maintenance due to the lack of gears.
- Slew speeds up to 50 degrees/sec for satellite tracking and fast target acquisition.
- Sidereal tracking accuracy of < 0.30 arcseconds RMS over 5 minutes.
- High resolution optical encoders on both axes for precision feedback.
- Can be installed in either equatorial, or alt/az configuration.
- Includes PWI4 software (ASCOM compliant) for mount control.
Description
The PlaneWave Instruments CDK20 is a 20 inch (0.51 m) f/6.8 Corrected Dall-Kirkham Astrograph telescope. The CDK20 has a dual carbon-fiber truss design, with 3 cooling fans ejecting air from the back of the telescope. The CDK20 covers a 52 mm field of view without any field curvature, off-axis coma, or astigmatism. The instrument weight is 140 lbs (64 kg) and comes standard with a back plate retaining ring ready to accept the focuser of your choice.
All CDK20 telescopes come with fused silica primary and secondary mirrors.
The L-Series combines versatility, simplicity and affordability by combining all the technology of our Observatory class telescopes into a compact stand-alone mount. In its Alt/Az configuration it is considerably more compact than its equatorial counterpart, allowing a larger telescope to fit in a smaller enclosure. The mass it takes to make a rigid alt/az mount is substantially less, leading to cost savings. Unlike German Equatorial mounts, there are no meridian flips to deal with, and no large protruding counterweights to create a dangerous hazard in a public observatory. Alt/Az is more intuitive to use and no polar alignment is needed. Besides, it is the way the pros do it!
L-Series Mount Features:
- Direct-drive motors on each axis for smooth, fast, and virtually silent movement of the telescope
- Slew speeds up to 50 degrees per second
- High resolution encoders on each axis for precise positioning
- Zero backlash
- Zero periodic error
- PointXP mount modeling software
- Enclosed electronics
- Through the mount cabling
CDK-500 + Core Accessories:
Item Number | Description | Price |
200130Q | CDK-500 (CDK20 / L-500) | $47,000 |
600180 | IRF90 Rotating Focuser | $ 4,500 |
200901 | EFA, Focuser Accessory Control | $ 800 |
Total | $52,300 |
Specifications
Mount System
Type | Alt-Azimuth / Equatorial Direct Drive Mount |
Weight | 257 lbs (100 kg) |
Component Weights | Azimuth Base – 121 lbs, Fork Arm – 136 lbs |
Max. Load Capacity | 200 lbs (91 kg) |
Latitude Range | 0 to 90 degrees, Northern and Southern hemispheres |
Cable Management | Equipment cables can be wired through mount |
Control System
Control Electronics | PlaneWave Interface dual axis telescope control |
User Interface | PlaneWave Interface 4 (PWI4) Control Software with integrated PointXP mount modeling software |
Homing Sensors | Home position sensors are included allowing the mount can find its home position on power up. |
Slew Rate | 20 degrees per second (standard); 50 degrees per second (maximum), both axes |
Power Requirement | Accepts 120 VAC. Supplied with 12VDC 15A Regulated Power Adapter |
Optical System
Aperture | 20 inch (508 mm) |
Focal Length | 3454 mm (135.98 inch) |
Focal ratio | F/6.8 |
Central Obstruction | 39% of the Primary Mirror Diameter |
Back Focus from Racked in Focuser | 5.8 inch (147 mm) |
Weight | 140 lbs (63.5 kg) |
Motion Control
Motor Control | Industrial grade brushless motor control system and built in electronics |
Motor – Azimuth and Altitude | Direct Drive 3 Phase Axial-Flux Torque Motors |
Encoder – Azimuth and Altitude | 152mm stainless steel encoder ring with reader built into the azimuth and altitude axes. 18,880,000 counts per revolution (0.069 arcsecond resolution). |
Motor Torque | Approximately 20 ft-lbs continuous; 50 ft-lbs peak |
Drive Electronics | Industrial grade, off-the-shelf brushless motor drives for each axis with custom designed interface card |
Telescope Control Software | PlaneWave Interface (PWI4). Incorporates PointXP mount modeling software by Dave Rowe. Provides HTTP and ASCOM control interfaces. |
System Performance
Pointing Accuracy | <10 arcsecond RMS with PointXP Model |
Pointing Precision |
2 arcseconds at sidereal velocity |
Tracking Accuracy |
< 0.3 arcseconds over a 5 minute period at sidereal velocity |
System Natural Frequency |
10 Hz or greater |
Included Items
Heating elements for dew prevention | The heating pads on the primary and secondary mirror require the 600195 Delta-T controller sold separately |
OTA Cover | To protect the primary mirror and inside of the optical tube |
Flashdrive | Contains software and instructions for collimation and spacing the primary to secondary mirror |
Hardware | Six 1/2-13 x 1 1/4″ socket head cap screws to bolt the mount to the pier, or wedge
Six 1/2-13 washers One extended length shoulder bolt for RA axis to EQ wedge alignment |
One 16′ USB cable | To connect the mount to the observatory control computer |
One 120VAC power cable | To provide power to the mount |
Standard Allen Key set | For tightening bolts used on the mount |
Flashdrive | Contains PWI4 software for mount control and instructions for installation |
Gamepad | Used for control of the mount tracking speeds for visual observing |
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